question about possible worn gasket behind bathtub overflow plate

[mknop1]

I had a plumber look at a leak in the ceiling below my bathroom. It turns out the leak is coming from the bathtub. I know that a worn gasket behind the overflow cover can cause leaks. I asked the plumber to remove the cover so we could take a look. He refused. Why would he refuse to do that?
I was paying him for his time. He seems to think it could be something more extensive than a worn gasket but all I asked was if we could just take a look behind the cover. He had an objection to simply unscrewing the cover plate. I don't get it. Is there some other problem that could result from only removing the plate and nothing else? He would not explain, he just said NO.

This is the cover plate-
Covers 3-1/4" hole, 1 Bolt hole.

[Terry]

I'm sorry, that was not a service plumber.
He was looking for something he could wrap his brain around.

It's common for tub leaks to be caused by the upper rubber washer around the tub overflow.
That normally happens only if you have someone taking baths with an overflowing tub. Women take more baths like that, guys tend to shower more.
But if you stand just so, water can splash off the back and still hit the overflow and leak through.

Remove the screw and check it yourself. Hardware stores carry the replacement foam washers.

[jimbo]

On an old cover plate, there is always the risk the screw will be stuck and will break. But if the gasket is leaking, that HAS to be dealt with, and there are ways to handle a broken screw.